These 100x Black High Quality i-Shaped Hair Extension Clips with 100% silicone coating provides extra durability, while the silicone helps prevent them from sliding out of place once attached to your hair. They also protect your natural hair from damage and won't rust when you wash your hair piece. Each clip has been individually tested and is guaranteed to snap open and shut. The 3 holes on either side of each clip allow you to choose how securely you would like to sew the clips into your hair piece. Suitable for human or synthetic hair.